Re: [pushed] c++: Fix defaulted <=> fallback to < and == [PR96299]

[Jakub Jelinek via Gcc-patches]

On Tue, Dec 08, 2020 at 03:05:09PM -0500, Jason Merrill via Gcc-patches wrote:
> I thought I had implemented P1186R3, but apparently I didn't read it closely
> enough to understand the point of the paper, namely that for a defaulted
> operator<=>, if a member type doesn't have a viable operator<=>, we will use
> its operator< and operator== if the defaulted operator has an specific
> comparison category as its return type; the compiler can't guess if it
> should be strong_ordering or something else, but the user can make that
> choice explicit.

Thanks.

> The libstdc++ test change was necessary because of the change in
> genericize_spaceship from op0 > op1 to op1 < op0; this should be equivalent,
> but isn't because of PR88173.

So shall we announce that in cxx-status.html?

diff --git a/htdocs/projects/cxx-status.html b/htdocs/projects/cxx-status.html
index 23081245..403d6740 100644
--- a/htdocs/projects/cxx-status.html
+++ b/htdocs/projects/cxx-status.html
@@ -186,7 +186,7 @@
     <tr>
       <td rowspan=10> Consistent comparison 
(<code>operator&lt;=&gt;</code>)</td>
       <td><a href="https://wg21.link/p0515r3";>P0515R3</a></td>
-      <td rowspan=8 class="supported center"><a 
href="../gcc-10/changes.html#cxx">10</a></td>
+      <td rowspan=4 class="supported center"><a 
href="../gcc-10/changes.html#cxx">10</a></td>
       <td rowspan=10> __cpp_impl_three_way_comparison &gt;= 201711 </td>
     </tr>
     <tr>
@@ -200,9 +200,11 @@
     </tr>
     <tr>
       <td><a href="https://wg21.link/p1186r3";>P1186R3</a></td>
+      <td class="supported center"><a 
href="../gcc-11/changes.html#cxx">11</a></td>
     </tr>
     <tr>
       <td><a href="https://wg21.link/p1630r1";>P1630R1</a></td>
+      <td rowspan=3 class="supported center"><a 
href="../gcc-10/changes.html#cxx">10</a></td>
     </tr>
     <tr>
       <!-- from Belfast -->
@@ -312,7 +314,7 @@
     <tr>
       <td> Atomic Compare-and-Exchange with Padding Bits </td>
       <td><a href="https://wg21.link/p0528r3";>P0528R3</a></td>
-      <td class="unsupported">No (<a 
href="https://gcc.gnu.org/PR88101";>PR88101</a>)</td>
+      <td class="supported"> <a href="../gcc-11/changes.html#cxx">11</a> </td>
       <td> </td>
     </tr>
     <tr>

        Jakub